This invention is in the field of coin-responsive mechanisms, particularly those used in coin-operated display and sales cabinets for newspapers.
Such cabinets conventionally include a door which is normally latched closed, but which is unlatched and can be opened when the correct money is inserted. The present invention is mainly but not exclusively concerned with the coin-return facility of the mechanism.
It is a feature of such mechanisms that they include complementary latch members mounted one on the door and one on the fixed part of the cabinet. One of these latch members is movable, and is spring biassed to a normal position. In that position the latch members are engaged and the door cannot be opened. To open the door, an unlatching means is provided to overcome the spring biassing and to move the one latch member away from its normal position, and to move it enough for the latch members to become disengaged. Of course, it is arranged that the operation of the part of the mechanism that moves the movable latch member is dependent on the presence of correct coinage in the mechanism.
The means that causes the latch members to become disengaged in this fashion includes a chute-closure member that normally is spring biassed against the bottom of the chute, and prevents a coin in the chute from falling therefrom. The chute closure member is movable downwards, against the spring biassing. Like one or other of the latch members, the chute closure member is constrained to move with the door as the door is opened: as the door is opened, the chute closure member is withdrawn transversely away from the bottom of the chute. Coins in the chute therefore fall from the chute when this happens, and it is arranged that the money falls into an accepted-coin tray. The ability of the chute-closure member also to move downwards is made use of in the following manner: one way "check valves" are arranged in the chutes to trap coins in the chutes when those coins total the desired amount; now, when the door is drawn open, a coin contacting surface on the chute closure member engages the lowermost of the coins; the closure member is thus pressed downwards as it is withdrawn, since the coins are prevented from moving upwards by the valve. This downwards movement of the closure member is arranged to be the means whereby the one of the latch members is moved and disengaged to allow the door-opening movement to continue.
Although it need not be so, it is conventionally arranged that the movable chute-closure member and the movable one of the latch members are one and the same piece. The composite member is pivoted directly to the door, and the one pivot serves therefore for both the latch member, and for the downward movement of the closure member.
There are quite a number of other operative principles taught in the prior art for providing a latch that becomes disengaged when correct coinage is inserted in the mechanism. The principle described above, which may be termed the "trapped-coins-push-latch-down" principle, has led to the most successful mechanisms, because it permits the various components of the mechanism to be arranged neatly and simply.
It is relatively easy to design the component pieces so that they are all adequately robust, and adequately mounted, and so that they perform their functions and interactions with each other reliably, and can be made and assembled without difficulty; all in the manner of elegant engineering designs whatever the field of application.
Except, that is, for the coin-return facility. Accommodating a coin-return facility has hitherto prevented mechanisms based on this principle from realising the full potential degree of basic simplicity. The simple mechanism of a closure member spring-biassed against the bottom of the coin chute does not lend itself to the provision of a coin-return facility. The main difficulty lies in diverting the coins that are to be returned away from the entry to the accepted-coin tray and into the mouth of the coin-return tray.
One measure hitherto popular has been to provide a movable chute, which when a person presses a coin return button, moves so that the bottom of the chute is now over the mouth of the return tray. Such a movable chute is shown for example in U.S. Pat. No. 4,375,844 (FACTO, Mar. 8, 1983). The provision of a movable chute of course takes away most of the basic simplicity of the "trapped-coins-push-latch-down" concept.
Another measure has been to provide a sloping chute. Here, the chute is arranged to burst open when a coin-return button is pressed, and coins fall not from the end or bottom of the chute but from its intermediate length, and the return tray catches coins that fall in this manner. Only if a coin reaches the very end of the chute does it fall into the accepted tray. The chute does not have to move, which is a bonus, but the space taken by the sloping chute makes for mounting and fixing difficulties. U.S. Pat. No. 3,253,690 BREWTON (May 31, 1966) shows a mechanism like that.
Yet another measure taken to return the coins has been to work the cabinet door back and forth (through the small amount of travel permitted due to free play in the latch); an action that imparts an impulse to an improper coin to flick it into the return tray. Again, this detracts from the basic simplicity of the design. U.S. Pat. No. 2,925,898, issued Feb. 23, 1960 to TERRY, shows a mechanism like that.
Yet another measure has been to provide that the latch plate/closure member moves sideways. When the coin return button is pressed a scoop pushes aside the closure member, and moves into position below the chute (which in this case need not itself move). The coins in the chute fall onto the scoop and are diverted into the return tray. The latch plate/closure member has to be guided for sideways sliding as well as for its normal pivoting movement, and sideways sliding along a pivot pin is not an easy thing to accomplish in a trouble free manner particularly as the components are exposed to occasional abuse and vandalism and to extremes of the weather. U.S. Pat. No. 3,870,136 (VOEGELI, Mar. 11, 1975) shows a mechanism like that.